The present invention relates to a furniture drive for moving a flap of an item of furniture, including: at least one pivotally mounted actuating arm for moving the flap, a spring device for acting a force onto the actuating arm, a transmission mechanism for transmitting a force of the spring device onto the actuating arm in a closing direction and, after exceeding a dead-center position, for transmitting a force of the spring device onto the actuating arm in an opening direction, and an adjusting device by way of which a position of an actuating portion of the actuating drive can be adjusted in or along a guide.
The invention further concerns an arrangement with a flap of an item of furniture and with an actuating drive of the kind to be described.
Actuating drives of this kind can include a lever arrangement in the function of a dead-center mechanism (DE 102 03 269 A1). The spring device applies a closing force onto the actuating arm in a region near to the closed position and, after exceeding a dead-center position in which the hinge axes of the levers and the acting force vectors are in line, applies a torque towards the opening direction. Also known are dead-center mechanisms having an arrangement with a control curve and a pressure roller (DE 10 2004 019 785 A1), whereby the control curve is shaped such that the change of the torque acting onto the actuating arm is effected after having passed a dead-center position.
The force of the spring device is to be adjusted by an adjusting device according to the weight of the furniture flap to be moved, i.e. that the spring device has to exert a corresponding high torque onto the actuating arm in the opening direction when heavy furniture flaps are to be moved. With actuating drives having a dead-center mechanism, the adjustment also affects the closing force of the actuating arm which leads to the fact that the furniture flap, when a high torque acts onto the actuating arm in the opening direction, is also held with a corresponding high closing force in the closed position. The high closing force needs to be overcome by a considerable manual force applied by an operator when opening the flap until the dead-center position of the actuating arm is reached, whereupon the spring device assists the further opening movement.
Such flap fittings are described in DE 102 03 269 A1, EP 1 154 109 A1 and in DE 26 48 085 A1.
A further development is shown in EP 1 990 494 A1, wherein an effective torque can be adjusted in order to assist the closing movement and, on the other hand, the opening movement.
WO 2013/113047 A1 to the applicant shows an actuating drive for furniture flaps, the actuating drive can be switched between different operating modes by a switching device. By way of the switching device, a hinge axis which connects two levers of the actuating drive with one another can be adjusted along a guide. In a first operating mode, a closing force is exerted onto the actuating arm in or near the closed position so that a furniture flap connected to the actuating arm, at the end of the closing movement, can be pulled into the closed end position. By a displacement of the hinge axis along the guide, on the contrary, an opening force is exerted onto the actuating arm in or near the closed position in a second operating mode, so that the actuating arm, although being in the closed position, acts towards the opening direction. This has the particular advantage that, in the second operating mode, an additional ejection device for ejecting the flap starting from a closed position into an opening position needs not to overcome a closing force of the spring device exerted onto the actuating arm so that the furniture flap can also be ejected from the closed end position by way of a relatively low dimensioned force storage accumulator of the ejection device. For adjusting the spring force acting towards the opening direction, there is provided an adjustment device (FIG. 2, reference number 15) which is separate from the switching device. For the assembling person, there is thus the necessity that two separate adjustments need to be performed.